COLKOPTERA. 507 



Those, in which it does not exist, may form two subgenera, viz. 

 that of 



Amerhinus, 



Where the body is oval or almost cylindrical and convex be- 

 neath(l); and that of 



Baridius, 



Where it is depressed and rhomboidal(2). 



Those Rhynchaeni of Fabricius, in which the sternum presents a 

 cavity for the reception of the proboscis, have been arranged by M. 

 Schoenherr in a great many genera, which we will reduce in the fol- 

 lowing manner. 



They are either winged or apterous. 



Of the former, some are almost rhomboidal, with the thorax ab- 

 ruptly narrowed in the manner of a tube near its anterior extremity; 

 the abdomen is almost triangular. They are connected with the 

 Baridii. 



Here the antennae are composed of twelve joints. 



Camptorhynchus Eurhinus, Schcenh. 



The Camptorhynchi are distinguished from all the following sub- 

 genera by their antennae, which, from the bend, form a thick, per- 

 foliate club(3). 



Centrinus, 



Where the scutellum is distinct and the abdomen completely co- 

 vered by the elytra, the eyes are remote, and the club of the antennae 

 is elongated. There is frequently a tooth or horn on each side of 

 the cavity of the pectus(4). 



Zygops. 



Where the eyes are very remarkable, being extremely large and 

 closely approximated or united superiorly, as well as the generally 

 long legs, of which the posterior at least are very remote(5). 



(1) The genera Amerhinus, Netarhinus, Mcides, Solenopus, of Schoenherr. 



(2) The genera Rhinastus, Cholus, Dionychus, Platyonyx, Madams, Baridius. 



(3) M. Kirby having already applied the name of Eurhlnus to another genus of 

 this family, it became necessary to change the denomination of this one. 



4 ) See Schoenherr. 

 (5) His genera Zygops, Mecopus, Lechriops. 



